Self-locking electrical connector



March 24, 1953 H. J. MODREY 2,632,739

SELF-LOCKING ELECTRICAL CONNECTOR Filed Aug. 10, 1949 4 Sheets-$heet 1 Z6 INVENTOR.

March 24, 1953 H. J. MODREY 2,632,789

' SELF-LOCKING ELECTRICAL CONNECTOR Filed-Aug. 10, 1949 i 4 Sheets-Sheet 2 I INVENTOR.

A 7raz/z/zx 1 a N z, W I W 7 u w W A 1L H. J. MODREY SELF-LOCKING ELECTRICL CONNECTOR March 24, 1953 Filed Aug 10 1949 March 24, 1953 H. J. MODREY 2,632,789

SELF-LOCKING ELECTRICAL CONNECTOR Filed Aug. 10, 1949 v 4 Sheets-Sheet 4 INVENTOR. 1) Qz Patented Mar. 24, 1953 UNITED ISTAT ES PAT E'NT OFFICE S-ELF-LQGKING ELECTRICAL CONNECTOR Henry J. Modrey, Philadelphia, Pa.

Application August 10, 1949,, Serial No..109,525

14 Claims. 1

This invention relates to connectors. tor detachab-ly connecting electrical conductors. particularly to electricalconnectors the plug of which, vupon application .to thesocket, automatically locks itself to the same until released by manipulation of the. connector. The connectors may either be of the. single pole type or the multipoletype.

One of the objects .of thepresent invention is to provide. a novel and. improvedmoisture and liquid proof, self-locking electrical connector of vthe general type, above referred to.

.Another object .of .the invention isto provide a. self-locking electrical connector of the general. type, above. referredto, the. plug and .socket of which form a tightly sealed unit when locked together.

. .Another object of the. invention .isto provide a novel and improved electrical connector the .plug of which seals itself automatically to. the

socket when applied to. the same.

. Another object of the invention. is to, provide .a novel. and improved electrical connector,

which is so. designed that the manner in which the connectormembersare applied to each other will be obvious. withoutspecial. instructions while separation of the two connector members will not be possible or at least be difiicult. without. instrucing the two connector members one against the other while for purpose of separation concealed release means must be manipulated by deformationof the plug casing. 7 .Another object. of the invention is to provide a. self-locking, self-sealing electrical connector of the-general type, above referred to, the contact, locking and release elements of which are protected against mechanical damage by. a substantially rigid .inner shell.

Other and. further objects, features and advantages of the invention will be pointed out hereinafter and set forth in the appended claims forming part of. the application.

In the accompanying drawing several now preferred embodiments, of the invention are shown by way of illustrationv and not by way of limitation.

In the drawing:

Fig. 1 is a sectional view of the plug andthe socket of anelectric'al connector accordingto the invention, the connector members being shown disengaged.

Fig. 2 is a plan view of the socket taken on line 2-2 of Fig.1.

Fig. 3 is a plan view of the plug taken on line 3-3 of Fig. 1.

Fig. 4 is a sectional view of the plug taken-on line 44 of Fig. 1.

.Fig. 5 is a sectional view of the connector of Fig. l, the connector'members being shown in 9-9 of Fig. 7.

Fig. 10 is a sectional view of theplug taken on line l0.llliof Fig. 7.

Fig. 11 is a sectional side view of another modification of an electrical connector according to the invention, the socket and the plug being. shown disengaged.

Fig. l2 is a fragmentary sectional view of a connector similar to the connector of Fig. 11 showing the connector members in an engaged position.

Fig. 13 is a fragmentary sectional view of the connector of Fig. 12 showing the plug in a-position ready for disengagement from the socket.

Fig. 14 is a sectional 'side view of still another modification of an electrical'connector according to the invention, the connectormembers being shown in an engaged position.

Fig. 15 is a sectional side view of still another modification of an electrical connector according to the invention, the connectormembers being shown disengaged, and

Fig. 16 is a fragmentary sectional view of the socket of Fig. 15 taken on line |5l6 of Fig. 15.

Referring first to Figs. 1 to 6 in detail, the electrical connector according to these figures comprises a socket!!! and a plug 2!. The socket is shown as a panel socket including a plate 22 which may be fastened to a base by any suitable means, such as screws. Of course, plate 22 can also be part of the panel itself orof a wall memher. The plate can be made of metal or, as shown, of a suitable insulation material such as a plastic or rubber. It has a central hole 23 in which is tightly fitted a metal plate 24 having a countersunk axial bore 25. The plate 24 constitutes the socket contact element and may be connected to a wire 29.

Plug 2| comprises a substantially rigid, electrically conducting clamping rod 26 disposed within a flexible shell 2'! made of rubber or any other suitable material. The forward or engaging end of rod 26 ends in an enlarged clamping head 28 which may be formed by bending back the rod material. As will be noted, head 23 is eccentric relative to the rod axis. The inner end of the rod is connected to a wire 29 and secured against axial displacement relative to the shell by any suitable means such as a-disc 30 inserted in the shell wall. It is of course also possible to secure wire 29' within the shell. The forward end of shell 21 supports a wall member shown as a plate 3| having an axial opening 32 therethrough. Wall member 3! may also be integral with shell 21 and form part thereof. A wedging slide 33 is extending through hole 32 alongside rod 26 and slidably relative thereto. The inner end of the wedging slide is secured to the wall of shell 27, for instance by means of a flange 34 engaging a corresponding recess in the shell wall. The wedging slide, of course, may also be designed as an extension of the shell proper. As will be noted, the tip of both the clamping head and the wedging slide are rounded with the tip of the clamping head extending beyond the tip of the wedging slide. The common axis of the wedging slide and the clamping rod is coaxial with the axis of plate opening 25. The combined crosssection of the wedging slide and the clamping rod just below the clamping head corresponds substantially to the cross-section of plate opening 25 while the combined cross-section of the wedging slide and the clamping head is larger than the cross-section of plate hole 25 so that the clamping head will overhang plate hole 25 when passed through the same.

The wall of shell 21 is slightly outwardly curved to facilitate transverse expansion of the shell, as will be more fully explained hereinafter, and supports two knurled collars 35 and 36 respectively forming grips. The forward end portion 3'! of shell 21 is so shaped that it can be fitted into the socket cup defined by the wall of socket opening 23 and plate 24.

As will be noted, rod 26 with clamping head 28 which form the plug contact element are shown as round poles. In this connection it should also be noted that the connector according to Figs. 1 to 6 can also be designed as a multipole connector instead of single pole connector as shown.

Let it now be assumed that it is desired to apply the plug to the socket. Then, the operator grips shell 27, preferably near its rear end, and presses the plug against the socket with the protruding tip of clamping head 28 inserted into plate hole 25. As a result, the tip of wedging slide 23 abuts against the edge of plate 24 and is pressed back relative to the clamping head, the flexibility of shell 2? permitting such relative movement. As will be obvious, the backward movement of the slide will cause a shortening of the axial length of the shell compelling the shell walls to expand outwardly. At the same time, the deformation of the shell will store tension in the shell. Upon continued forward movement of the plug toward the socket, coupled with a slightly transverse movement, the forward end portion 37 of the plug will enter the socket cup until the face of the plug abuts against plate 24. During this continued forward movement of the plug, the clamping head 28 passes completely through plate hole 25 so that the rod portion just below the clamping head is now within: hole 25, thereby leaving space for the wedging slide to enter hole 25. The hole is now substantially filled by the combined cross-section of the wedging slide and the clamping rod so that the overhanging portion of the clamping head prevents a withdrawal of the clamping head through plate hole 25, thereby locking the plug to the socket with the contact elements in engagement so that the two wires 26 and 29 are electrically connected.

Fig. 5 illustrates the positions of the various connector parts at the end of the previously described operations. As will be evident, the tension stored in the shell by the deformation of the shell wall presses wedging slide 33 forwardly. Furthermore, the deformation and expansion of the shell cause the forward end portion 3'! thereof to expand or swell within the socket cup so that the shell wall presses itself tightly against the wall of socket opening 23 with the rim of collar 35 abutting against the face of socket plate 22. In other words, the non-expanded forward end portion of the plug is inserted in the socket recess and then so expanded in size that it could not enter the said recess in its expanded condition. As a result, a tight seal is formed between the plug and the socket which is moisture and water proof for all practical purposes and which has withstood severe tests in this direction.

After the plug is sealed to the socket, neither a simple pull on wire 29 or the shell nor a compression of the shell wall will result in a separation of the plug. A pull on wire 29 will simply press head 28 tighter against plate 24! and a. compression of shell 2! will have no effect whatsoever. Only if the shell is gripped, preferabl at collar 35, and further shortened by axial compression, the plug will be released by retraction of wedging slide 33 from plate hole 25. Fig. 6 clearly illustrates the release operation.

Figs. 7 to 10 show a connector design which is similar to the previously described design with the exception that the plug contact element is shown as a fiat prong. Accordingly, clamping rod 26', clamping head 28 and wedging slide 33' have a rectangular cross-section as can best be seen on Figs. 9 and 10. Plate hole 25 has also a corresponding rectangular cross-section. Clamping rod 26' engages the shell wall directly by means of a lateral flange Mi and has an extension 41 to which wire 29 is secured.

The operation of the connector according to Figs. '7 to 10 will be obvious from the previous description. As will be apparent from an examination of Figs. 1 to 10, substantially the only protection of the contact elements of the connectors shown in these figures is furnished by the flexible shell 21. For certain applications, it is preferable to provide a stronger mechanical protection for the contact elements and the operating mechanism of the connector. Figs. 11 to 13 show a connector design the inner parts of which are armored against mechanical damage.

First referring to Fig. 11, the socket of the connector according to this figure comprises an outer shell 45 made of insulation material such be *more; fully explainedv hereinafter.

as rubber or plastic. The outer shell houses an innermetalshll show-nas comprising a sleeve Wand; :a metal :cup' l'l secured to; sleeve 46. Cup "is "connected to wire 4'8 and hasat its .forward or'receiving end a preferably inwardly drawn wall member 49 including an axial holeltll. Wall. member 49 together with part of the wall. ofishell 4L6 forma receivingcup E l for the-:plu .As will be'notedwall portionsEvcfinsulaticn shell 4:5 adjacent to cup52lis tapered toward'the receiving end of the socket.

The plug of the connector comprisesan outer flexible insulation shell 55 made for instance of rubber. Shell 55 isopen-at its forward or engaging'end and closed at its opposite end. Outer shell 55 houses a substantially rigid innershell 56, preferably made of metal so that it can be connecteddirectly to wireil. Shell 56 hasa cupshaped extension 53 which serves to receive the inner end of a substantially rigid electricallyconducting clamping rod 59 having anxeccentric clamping head ti! on :its :outerend. The.:plug further comprises a. wedging slide 6! disposed alongside the -'-clamping rod 'slidably relative thereto. The clamping: rod andthe wedgingslide are extended through an opening 62 of a guide member t3: which'is shown as'a substantially rigid cup, preferably made of metal. Cup 63 is telescoped vupon'inner shell 56 and'preferably has an outer collar or flange 54' thepurpose of whichwill A loaded coil? spring fiiabutting with one and against the bottom of the inner or the outer shell and with its other 1end,..-against a fiangefifi urges the. wedging,

slide and with. it cup E3 toward. the clamping head.

As will be apparent, the forward movement of cup :fifiislimited by the clamping head being seated against the outside of the .cup'bottom. A washer-1&1: maybe provided toad-just. the position of the wedging slide relativevto the clamping head and-also to stabilize the entiremechanism.

The relativecross-sections of the wedging slide, the clamping xrod, the'clamping head :and socket holeicraresimilar to those. of thexcorrespending part of the connectors according to Figs. 1 too.

The innerdiameter of :outer flexible shell 55, particularly of the forward end'portionoi" the said shell, is so selected that it will fitiupon the narrow part of the tapered-portion 5.2 of socket she'll but not overawider .part ofi said socket shell portion without radial expansion of? shell "The connector accordingto-Figs. I2'.an'd;rl3: is similar 'in all respects to the connectoraccording to Fig. llwith the exception that the forwardiend portion of flexible shell 55 is reinforced or beaded attfi.

The function of the connector according toliig. l 1 i and of the connector according .toFi-gs- '12:.and 13' is the same so that the subsequent description of function will apply t .Eigs.- l1.to.13'..

As will be noted, the inner rigid shells-and sleeves of the connector members encase the contact elements, the springet'c. completely so that the inner mechanism of the connector is protected against mechanical damage within-the .lim-itsrs'of the mechanical strength of the-aforesaidshells and sleeves.

r Let it now be assumed that itis desiredt apply the. plug to. the socket. Then, the operator grips shell 55 and presses the -plug against the socket. As; a result clamping head will pass through hole=5li and 'wedging. slide El willenter hole 50 alongside the clamping rod after the clamping head hascompletelypenetrated hole 50. .Theiorward portion of cup 63vwil1be'received'by cupr5l of the socket. The various relativedisplacements of the elements of the-clamping head and the wedging slide will be easily understandable from the description ofFigs. 1 to 6. By. reason of the recession of wall member to including'hole 5i! and of the fact that the position of cup '63 is determined by the circumference of wall member 49, cup 63 is telescopeddeeper uponshell 56, as can be easily ascertained by a comparisonof Figs; 11 and 12, the latter figure showing the plug applied to the socket. Consequently, the axial'distance between the bottom of shell 55 and the bottom of cup 63*is shortened. In other words, the bottom of cup 53 is retractedrelative to the edge of shell 55. As will be apparent, shell 55 is slipped with its forward end portion upon tapered socket shell portion 52 while the plug is pressed toward the socket. As the movement of the plugtoward the socket continues, the edge of shell 55 reaches a part of tapered portion 52 which is wider than the inner diameter of shell 55. Consequently, the shell is forcibly expanded. At the same time, the aforementioned shortening of the operative length of the plug mechanism forces shell 55further upon the socket shell, thereby causing a radial expansion and a certain axial shortening of the plu shell.

The final result is that the flexible plug shell seals itself automatically to the socket shell, 1 as can be clearly seen'on Fig. 12. The heading of shell so according to Figs. 12 and 13 further contributes to the creation of a tight seal between. the connector members.

It will be obvious that the application of the plug tothe' socket does not require any special instructions since thetessential parts are clearly visible when the plug is detached.

' Let itnow be assumed that it is desired to detach the'plug from the socket. Then, the operator grips shell 55 andpushes the same further toward the socket whereby the clamping head assumes the protruded position shown on Fig. 13. Finally, the operator squeezes shell 55 together, thereby holdingcup 63 in itspushed-inposition relative to shell 56 in which the clamping head protrudes as shown on Fig. 13. The plugcan now be simply withdrawn .from' the socket, slide 6| noIOngerpreVenting' such withdrawal. As will benoted collar orridge it facilitates holdingcup 5.3 in the pushed-win position relativeto shell 56-. .As' scenes the plug is withdrawn, the transverse pressure upon shell-55 can be released whereupon the'variousparts of the plug mechanism return into the position shown in Fig. 11.

It: will beevident that thepeculiar manner by which the-plug must be released will not be obvious without familiaritywith the design of the connector; thereby protecting circuit connections closed by the connector against unauthorized'interference.

'Fig. 14 shows an electrical connector the socket ofwhich comprises an insulation 'member to which may be fastened toa panel byanvsuitable means: or formp-artpf' a panel. Insulation member 10 includes anopening in which is tightly fitted a metal plate H constituting the contact element of the socket and connected to a wire '12. Plate H has an axial opening 73 which serves to receive the contact element of the plug. This latter contact element isshown as a metal tube 14 housediwithinand secured. with its inner end to a flexible socket shell 15 made for instance of rubber. A cross pin 16 serves to secure the metal tube within the socket shell. An extension 1'! of the tube is connected to a wire 18. The locking means of the connector comprise a wire spring 19 disposed within contact tube M. Spring 19 has a nose 89 arranged to extend through a slot 8| of tube M and a second nose in form of a loop 82 arranged to extend through a second slot 83 into tube 14. Spring 19 is so shaped and biased that normally noses 89 and 82 protrude from the tube as is shown in full lines. Nose 80 serves as a locking element and nose 82 as a release element. Adjacent to loop 82, a button 84 may be provided on the outside of shell 15 to facilitate manipulation of the release element as will be more fully explained hereinafter. As will be apparent, nose 89 is so shaped that this nose will be forced back into the tube when the latter is inserted into plate hole 13 for the purpose of applying the plug to the socket. As soon as tube 14 has penetrated sufilciently into plate ll, nose 89 snaps back into its original position, thereby locking the plug to the socket. During the insertion of tube 74 into plate hole l3 the forward end portion '55 of shell 15 enters the cup of the socket. The cross-section of shell portion 15 is so selected that it fits easily into the socket cup while the plug shell retains its natural configuration. However, when the forward edge of shell portion 15 reaches the bottom of the socket cup the flexible shell is axially shortened and compelled to expand transversely as the penetration of tube 14 into socket hole is progresses. Consequently, the plug shell seals itself tightly to the socket.

When it is desired to release the plug from the socket, pressure is exerted upon button 84 thereby forcing the spring into the position shown in dotted lines in which the plug can be conveniently withdrawn from the socket.

Figs. 15 and 16 show an electrical connector design in which the socket comprises a shell 99 made of rubber or any other suitable insulation material. Shell 99 houses a contact element 9! which is connected to a wire 92 and has a central axial slot 93 (see Fig. 16) for the reception of a correspondingly shaped plug contact element 94.

The plug comprises a flexible shell 95 made of rubber or any other suitable insulation material. Plug contact element 94 is housed within shell 95 secured against axial displacement relative to the shell and connected to a wire 96.

The locking means of the connector are shown as being of the bayonet type and comprise a sleeve 97 rotatably supported on contact element 94. This sleeve includes a slanted bayonet slot 98 ending in a locking groove 99. Slot 98 coacts with a pin I99 secured to socket contact element 9|. A coil spring IOI fastened at one end to contact element 94 and at the other end to sleeve 91 serves to hold the locking means in locking position and also to facilitate the release of the plug. The sealing of the plug to the socket is again effected by providing a tapered portion 99 of the socket shell upon which portion the plug shell is forced.

When it is desired to apply the plug to the.

socket the tip of contact element 94 is inserted in socket slot 93 and the plug and the socket are pushed together. As pin I99 engages slot 98 and slides in the same, sleeve 91 is rotated relative to contact element 94, contact element 9! being stationary. Consequently, spring ll is loaded and as pin I90 finally slips into groove 99 it is safely held therein by the spring tension.

As the connector members are pressed together, and the forward end portion of plug shell 95 slips further upon tapered shell portion it is compelled to expand transversely, thereby again securing a tight sealing connection between the plug and the socket as was previously explained in detail.

When it is now desired to disconnect the plug, sleeve 97 is manipulated by transversely compressing shell which is preferably provided with a ridge 92 for this purpose so that pin I00 jumps out of locking groove 99. Consequently, spring [9| which is now released will rotate sleeve 91 back into its original position thereby opening the bayonet lock and with it releasing the plug.

It will be evident that the connectors according to Figs. 14 to 16 are also so designed that the application of the plug to the socket is obvious while the separation of the connector members requires instruction.

Finally, it should be mentioned that the connectors according to Figs. 11 to 16 could also be designed as multiple connectors and may be equipped either with round poles or with flat poles.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In an electrical self-locking connector for detachably connecting electrical conductors, in combination a socket member including an electrically conducting portion having an axial hole therethrough, said portion constituting a receiving contact element; a plug member comprising a substantially rigid inner sleeve housing an engaging contact element protruding at one end from said shell and engageable with said receiving contact element, an outer flexible shell surrounding said inner shell; locking means supported by said plug for locking the said contact elements together when engaged; and release means supported by the plug for unlocking the contact elements, the said release mean including an operating member arranged to be engaged and manipulated for release of the contact elements by deformation of the flexible shell, the forward end portions 'of said outer shell and said socket being shaped to receive one the other when the connector members are applied to each other, said engaging contact element being secured against axial displacement relative to the rear end portion of the flexible shell, the axial length of the flexible shell being so that the said shell is shortened and transversely expanded when the contact elements are in engagement for causing a tight fit between said expanded flexible shell and said socket, thereby effecting a tight seal between the plug and the socket when joined.

2. In an electrical self-locking connector for de'tachably connecting electrical conductors, in combination'a socket member including an electrically conducting portion having an axial hole therethrough, said member constituting a receiving contact element; a plug member comprising 18% flexible outer shell, and a substantiallyrigid innerrshell disposed. within said outer shell, a

guide member having an opening theret'hrough sli'dably supported by the inner shell, a substantially rigid electrically conducting clamping rod disposed within the inner shell slidably extending -with one end through said guide member opening to form an enlarged clamping head out side the guide member, the other end of the clamping rod being secured against axial displacement relative to the outer shell; a wedgln slide extendingalong the clamping rod anddisplaceablex conjointly with said guide member relative to the inner shell; and loaded spring means within .theinner shell-biasing the guide member toward the. clamping head, the forward end portions of said outer shell and said socket being shaped, to receive one the other when the connector members are applied to each other, and

the axial length of the outer flexible shell being so that the said shell is axially shortened and transversely expanded when the contact elements are in engagement for causing a tight fit between said expanded outer shell and said socket, thereby effecting a tight seal between the plug and the socket when joined.

3. An electrical connector as described in claim 2, wherein said forward end portion of the socket member is tapered toward the receiving end of the socket member, part of said conical socket portion being wider than the cross-section of the flexible plug shell, when unexpanded, to obtain a tight sealing fit between the plug and the socket.

4. An electrical connector as described in claim 3, wherein said electrically conducting socket portion is cup-shaped and arranged to receive said guide member when the plug is applied to the socket, the bottom of said cup being retracted relative to its circumference.

5. An electrical connector as described in claim 2, wherein said guide member is cup-shaped and telescoped upon said inner shell, the bottom of said cup including said opening.

6. An electrical connector as described in claim 2, wherein said guide member is cup-shaped and telescoped upon said inner shell, the bottom of said cup including said opening, and wherein a collar is'provided on the outside of said cup to facilitate gripping and holding of the guide member through the flexible shell.

1 7. An electrical connector as described in claim 2 wherein said inner shell is closed at its end opposite to its engaging end, and wherein said inner shell and said clamping rod both abut against and are secured to the bottom of the outer shell.

8. An electrical connector as described in claim 2; wherein the relative length of said clamping rod and of the flexible shell are so selected that the axial distance available for the flexible shell when the plug as applied to the socket is shorter than the axial length of the said shell, thereby causing the aforesaid shortening and transverse expansion of the flexible shell.

9. In an electrical self-locking connector for detachably connecting electrical conductors, in combination a socket member including an electrically conducting portion having an axial hole therethrough, said portion constituting a receiving contact element; and a plug member comprising a flexible shell housing an engaging contact element protruding at one end of the shell and adapted to extend through said conducting 10 socket portion in contact therewith when-the plug is applied to the socket, spring actuated latchmeans supported bytheplug contact element, said latch means including a movable locking-element spring biased to protrude from said portion of the plug contact element extending I through said socket portion "hole, thereby looking the plug to thesocket, and release means supported by the plug contact element for moving said locking element into a release position, said release means being positioned and arranged to be manipulated by deformation of said flexible shell, the forward; end. portions of said plug shell andsaid socket being shaped to receive one the other when the connector members are applied to each other, and theaxial length of the plug shell being so that the said shell is axially shortened and transversely expanded when the .contact. elements are in engagement for causing a tight fit between said expanded shell and said socket, thereby effecting a tight .seal between. the plug and the socket when joined.

10. An electrical connector as described in claim 9, wherein said socket member includes a cu shaped portion, the bottom of said cup being formed by said electrically conducting socket portion, said cup being arranged to receive said forward end portion of the flexible shell.

11. An electrical connector as described in claim 9, wherein said plug contact element is substantially tubular and houses said spring biased locking element, said element being arranged to protrude from a lateral slot in the plug contact element, and wherein said release means comprise a nose extending from a second lateral slot of said plug contact element, said nose controlling the position of the locking element and being positioned to be manipulated for moving the locking element into the release position by transversely compressing said flexible shell.

12. In an electrical self-locking connector for detachably connecting electrical conductors, in combination a socket member including an electrically conducting portion having an axial hole therethrough, said portion constituting a receiving contact element; and a plug member comprising a flexible shell housing an engaging contact element protruding at one end of the shell and adapted to extend through said conducting socket portion in contact therewith when the plug is applied to the socket, spring actuated latch means supported by said plug contact element, said latch means comprising bayonet lock means, one of the contact elements having a slanted bayonet slot ending in a recess and the other having the bayonet pin, and spring means acting upon said contact elements for holding the same in engaged and locking position, and release means supported by the plug contact element for moving said bayonet locking means into a release position, said release means being positioned and arranged to be manipulated by deformation of said flexible shell, the forward end portions of said plug shell and said socket being shaped to receive one the other when the connector members are applied to each other, and the axial length of the plug shell being so that the said shell is axially shortened and transversely expanded when the contact elements are in engagement for causing a tight fit between said expanded shell and said socket, thereby effecting a tight seal between the plug and the socket when joined.

13. An electrical connector as described in 11 claim 12, wherein a sleeve is rotatably mounted on one of said contact elements, said sleeve having one of the bayonet lock elements, the second bayonet lock element being on the other contact element, said sleeve being rotated when the contact elements are applied to each other and the bayonet lock pin slides in said slot, and wherein a torsion spring is secured at one end to said sleeve and at the other end within the flexible shell, said spring being loaded by a rotation of said sleeve in response to an axial compression of the shell for holding said pin in the slot recess, thereby causing a locking of the contact elements in engagement by the action of the spring 14; An electrical connector as described in claim 13, wherein said sleeve slot having said recess and said bayonet lock pin are shaped and positioned relative to each other so as to lift the said pin out of the recess in response to an 20 axial elongation of the shell. thereby releasing the loaded spring means for return of the sleeve into a position for separation of the contact elements.

HENRY J. MODREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,127,544 Von Holtz Aug. 23, 1938 2,396,872 Miller et al Mar. 19, 1946 2,423,250 Modrey July 1, 1947 2,427,297 Modrey Sept. 9, 1947 2,444,843 Modrey July 6, 1948 2,448,509 Antony, Jr., et a1. Sept. 7, 1948 FOREIGN PATENTS Number Country Date 128,212 Austria May 10, 1932 

